At the Kaleen exhibition last year, one layout was running a train made up of both Powerline and Austrains S cars.
The only way you could tell that they were different when the train was moving was that the Tuscan and Russet colours were different.
I drew this to John Eassie's attention since he was responsible for both models, the Powerline models being released by John under the Trax label.
This was despite the Austrains models having correct roof ventilators while the Poweline models had only "Half relief" ventilators.
When the train was stopped, it was clear that the Powerline models had recessed window glazing and slightly smaller window openings but as far as could be seen they were both the same overall size and shape.
John is now only offering FS cars as part of the three car mail van pack, although some of these are being offered at exhibitions removed from the packs.
If flush glazing could be added to the Powerline cars and you only ran cars of different colour schemes together (Say Austrains Indian Red with Powerline Tuscan and Russet - which would be prototypical up to the mid 1960s) the effect wouldn't be too bad. Of course the two manufacturers could get together and match the colours for future production....
> Of course the two manufacturers could get together and match the colours for future production....
And the pigs are fueled up and ready to take off (and i'm not referring to a 36 Class Pig)!